Projector



Filed June 13, 1932 R. L. LEE

PROJECTOR 2 Sheets-Sheet l March 3, 11536.

Filed .Ju-ne 15. 1932 R. L. LEE

PROJECTOR 2 Sheets-Sheet 2 replacement.

Patented Mar. 3, 1936 .UNITED STATES PATENT OFFICE Y PROJECTOR Ralph L. Lee, Dayton, Ohio, assignor, by mesne l assignments, to Motion Picture Engineering Company, a corporation of Michigan v Application June 13, 1932, Serial No. 616,925

141 claims. (c1. sii-24) This invention relates to picture projectors.

One of the principal objects of the invention is the provision of a compact, readily portable projector of simple construction embodying an assembly of parts securely held in proper operating alignment and readily accessible for inspection or Another object of the invention is the provision, in a projector, of a picture illuminating lamp andI a contiguous heat radiator arranged for effectivel dissipation of the heat generated within the lamp.

Another object of the invention is the provision of a projector having a body portion in which are crossed slots providing a closed lm chute and a mount for loosely receiving aperture glasses.

. Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings, which illustrate apreferred embodiment of the invention,-

Fig. lis a side elevational view of a projector constructed in accordance with this invention;

Fig. 2 is a top plan view of the projector;

Fig. 3 is a longitudinal sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a side elevational view of the light source unit;

Fig. 5 is a front elevational view of the light source unit; f

Fig. 6 is a sectional view taken on the line C--l Fig. I is a verticalsectional view taken on the line' 1--1 of Fig. 3;

Fig. 8 is a sectional view taken on the line 9 3 n a of Fig. 1; and

Fig. 9 is a sectional view taken on the line S of Fig. 8.

. The drawings, in which like characters of reference designate like parts throughout the several views thereof, illustrate a projector which comprises vgenerally a nlm guiding body I0 embodyl in g the two connected body portions II and I2 which are shown formed as metal castings. Body portion II has an integrally extending lug I3 for the attachment of supporting legs I4. 'A light source, designated generally by the numeral I5;

is mounted within a shell I6 that is'permanently attached to the: body I3. The focusing lensv Il is slidably mounted in the supporting body portion I2 which is securely joined to the 'body portion I I.

A 1m` carrier 2li is also attached to the body Il,

the various parts mentioned. forming a rigid and compact assembly.v

- The body portion II is formed with a flat end 22 from which a substantially rectangular sleevelike portion 23 projects for attachment of -the shell I6. A tubular portion 24 projects from the sleeve portion 23 through a hole in the shell I6 5 I and forms a support in which the condensing lens 25 is received.- The condensing lens is constructed with a cylindrical metal exterior wall 26 which is slidably received within the cylindrical bore 21 of the body extension 2 4. Entrance of the lens 10 25 within the part 24 is limited by a shoulder 28. Its unintentional removal from assembled position,l is prevented by its close proximity to the lamp source. f

The generally tubular lens supporting member 15 I2 has a nat end 33 that is generally similar in form to the iiat end 22 of the body portion II. These flat parts are securely joined together by screws 34 and their abutting faces are slotted so as to provide a chute or guide 29 forthe passage 20 of a .film through a light beam projected from the rlight source I5 throughthe portions II and I2. The flat end 22 of the body portion II is provided with a rectangular light aperture 30 for the passage of the light beam from the light 25 source through the film whichis held within the guide or chute between the body portion II and the lens supporting portion I2. which is provided with a similarly shaped and aligned light aperture 3|.v As shown particularly in Fig. '7, the 30\.U abuttingl ends 22 and 33 comprise somewhat narrow portions at the sides of the portions II and I2. The remainder of the adjacent faces of these portions are cut away to a width to accommodate a4 nlm as indicated by the slot edges 36 '35 and provide clearance for the film which is guided along the surfaces .31. The. cut away partsdeflning the nlm chute 23 are of stepped depth; those portionsv defined by the faces 31 extending only fromI the sidewalls 36 of the slot inwardly an 40 amount suiilcient to form a rather close tting guide for the. edge portions oi the film, .while the remainder of the film is given additional clearance by provision of shallow grooves 39.4

'I'hat part of the film which is exposed to the 45 light beam between thelight apertures 30 and 3l passes between aperture glasses 40 that are loosely held within recesses formed in the abutting faces ot the portions II and I2. As shownithese aperture glasses are mounted within slots 4I that are 50 formed across the faces of the flat parts of the body portionl II and lens carrying portion I2 perpendicularly to the film chute 23. The slots 4I are of sufllcient depth to permit the nlm to pass between the adjacent faces of the aperture y yis from the carrier 20 down through the chute glasses -witn sunicient clearance that the film willr fixed to it a hand Awheel 69 which is provided not be scratched and yet willbe held closely with a knurled face 10 by which the operator enough to prevent curling upon exposure to the heat of the light source. A clearance of a few film perforations bear a denite relationship to thousandths of an inch has been found to be the illni framing and the sprocket size' is proquite satisfactory for proper passage of the nlm, 4portioned to spacing of" nlm holes so that the andto hold the film sufliciently at to provide sprocket movement necessary to advance the an undistortedimage. The glass slots 4I extend film by one frame is an aliquot fraction of one clear across the width of the parts I0 and I9 and revolution ofthe hand4 Wheel 69'.v In the illusthe aperture glasses are preferably substantially trated embodiment of the invention, 90 rotaof the same length as the slot. The-slot ends are tion of the hand wheel will advance the nlm by closed by metal cover plates 43 which are pivotally one frame. .i` y attached to the body portion II by screws 44. Retarding lmeans areprovidedso as to releas- The' plates 43 are frictionally held in vvposition ably hold thesprockets in positions wherein the by the tension of the screws 44 and by provision film frame is aligned with the light apertures 30 of a punched projection 46 which engages an and 3I. As shown, this retarding means is of a aligned depression in the side of the body part frictional character, and comprises a `detent against which each plate lies. When it is demechanism which engages depressed portions 12 sired to remove the aperture glasses it is only formed in the web part 13 of the hand wheel. necessary to swingaplate 43 around its mounting These depressions are spaced apart 90 -as is screw 44 as an axis, and this is readily accom. shown in Fig. 1. The detent mechanism is supplished through the provision of a finger operated projection 41 by which the plate may be and comprises a sleevev 15 xed to the bracket arm moved. The proportioning of the plate size and 62 and., enclosing a spring 16 that bears againsta the positioning of the attaching screw 44 is such ball 11 and presses lthis ball intoY engagement that upon swinging a plate through 90 from thel close-d position the glass\s1ots 4I are fully unto enter the depressions 12. Upon rotatingfthe covered for removal of the aperture glasses therehand wheel 69lits movement is frictionally refrom. n Y I sisted earch 90 upon the v'ball V11 entering a' de- 'Ihe travel of the film through thev projector pression 12. This same detent mechanism serves to frictionally hold the bracket 60 in a position 29 and out-the-bottomof the chute. Film advancing means are provided for moving the nlm relationship with the lm feeding' holes and a past thef light aperture in steps coordinated with position wherein the sprockets are removed from the film framing. To thread the film through engaging position.A The detent control for the the projector it is inserted within the film carrier bracket 60 comprises a ball 80 that is pressed by 20' which is' constructed of sheet metal that is the spring 16 against the lug 61 to engage in one formed into a semi-cylindrical portion 50 havholes for attachment to the projector by means positions the bracket for engagement of the of the same screws 34 that serve to hold the body 1 /'sprockets 55 with the nlm and frictionally resists portion II and the lens carrying portion I2 perf movement of the sprocket carrying bracket from manently'v assembled. The film end is thenI f this position. Movement of the bracket to the pushed down through the nlm chute and intoI on the fiat'part of the lens carrying portion I2.

:66 so that the bracketj66 may swing about the release position is limited by provision of a wire engagement with the film advancing means. 'To bail 84 which encircles the depending lug II and facilitate-the passage of the film the top edge hasinturned end portions 85 that are `received of the film chute is tapered or rounded of! as Within aligned openings 83 in the upturned parts indicated at 52, and the aperture glasses 46 are 62 of the bracket. rIfhelength of the bail is proalso .formed with curved edges 53 sothat the film portioned to preventmovenient of the bracket 6` beyond engagement( of the detentv ball 80 with may berea'dily pushed between them. y

the depression 82.

The nlm isfed through the machine by anY advancing mechanism that operates by a turning. V movement and is constructed to frictionallyresist pushed downwardly until the film end engages may advance the film feeding'sprockets 55.v The vported from `the sprocket carrying bracket 66 n or, the other of spaced depressions 8I and 82. Ening at one end a downturned lug 5I with screw 1 gagement of the ball within the depression 8| Having entered a film in the film chute `it is with the inner face of `the Wheel web portion 13 wherein the film sprocket is held in engaging *f film lmovement "at spaced'points corresponding the sprocket teeth. It thefilm end has been l to the lm framing. As`shown, the advancing trimmed in proper relationship to the nlm frammechanism comprises sprockets` 55' which are n ing, the engagement ofthe nlm vend with the nxedly mounted at opposite ends of a sleeve 56 sprocket tooth should frame the lmvr properly and are spaced apart thereon a distance correwith respect to the light apertures so that upon sponding tothe lateral spacing of theA advancing then 1lll'nine' the hand 'Wheel 20 the lm Will be holes on'the lm. The sprocket'sleeve is held to advanced by an amount to bring the next frame an operating shaft 51 by provision of a set screw into registration with the opening. -If, however, 58. This operating shaft' 51 is rotatably carried' the film end is not properly trimmed With IBSDEQ'G in a bracket 60 that is'supported from the-proto the framing it is only necessary `to swing the jector body portion I2. IAs shown, `the bracketl bracket 60 outwardly t0 permit, Afreeadjusting 60 is constructed of sheet metal and is formed 4 movement of the lm within the chute until a into U-shape comprising a nat portion 6| and frame is in proper registration whereuponthe upstanding arms 62 havingbarng openings 63 p bracket 60 is moved back so that the detent enfor `support; of the shaft 51. The .ends of the gages the depression 8 I and the sprocket teeth bracket arms 62 have fixed ,to them inwardly will then engage the ilm feeding holes. As menextending pins 65that are received within' axially tioned, the film feeding holes are proportioned aligned 'holes 66 in projecting lugs 61v formed to the film framingso that a 90. movement of the hand- 'wheel will providefor nlm 'advance of oneframe. W f

" The focusing lens I8 Ais a-sl'iding"t within the 9p ofthe lprojector portion I2 The pins 65 are a loose fit within the openings pins 65 as a center The end of the shaft I1 has cylindrical bore therefrom by an amount limited by the restriction 96 in the ball passage. l

The' film passing from the bottom of the film chute is directed outwardly by provision of a curved face 98 that is formed on the downwardly extending lug |3 of the body I9. As shown particularly in Fig. v'7, the guiding faces 31 on the lower ,part of the body portion II merge into a I curved face 98 on the lug which provides a smooth surface that directs the film endy forwardly and away from the projector legs or other parts of.

the machine which might cause it to become entangled. l

1 The light source for the projector is unusually small and compact, having a heat radiator of small size which keeps the apparatus cool. This light source preferably embodies a unit comprising a lamp, and acontiguous radiator in which the lamp is enclosed. The vincandescent lamp |99,as shown, is mounted within the contiguous ,metal radiator |9| for the effective dissipation of the heat generated by the lamp. The lamp |99 is provided with a bayonet type base having locking lugs |93. The lamp base is carried by a cylindrical socket |94 having cutaway portions |95 for engagement with the lamp base lugs |93. A connecting prong |96 is fastened at |91 to the socket sleeve |94 and provides one side of the connection to' a current supply plug |99. The end of the sleeve |94 carries an insulating bushing |I9 having an axial opening in which a pin is slidably mounted. This pin Hlprovides the other prong for engagement with the connecting plug |99 and serves also as a connection through to the base terminal I2 yof the lamp. As shown, the pin I is provided with an enlarged end I I4 and a spring I I5 is provided betweenthe enlarged end and the p insulating bushing 9. l'I'his spring urges the a lampsupporting member |29 which is formed l pin upwardly into contacting engagement wim-the' lamp terminal Hz and is limited 1n its upward movementby provision of a washer 'I I6 which is retained on` the pin l| by a lockingring I1. The lamp socket is slidably mounted within of some suitable insulating material, and is shownr as having a threaded portion |2| for engagement with the lamp radiator. The lamp socket is held to the'lamp supporting member |29 by provision of`a set screw |2I'. 'I'he posi-tion of threaded engagement of the lamp supporting member |29 withthe lamp radiator is fixed by contacting engagement of the fiat face |23`of the supporting member with the bottom edge-of the lamp radiator. By the provision of thesecontacting faces lthe* lamp supporting member always"screws into the lamp radiator into contacting engagementat the same place. l

lThe arrangement of parts? that has just been l vdescribed provides a focusing adjustment for the lamp. d Lamps for projector service are constructed so thatthe greatest amount of light can bedirected toward the film for effective projection.

As shown, the lamp illustrated has its filament arranged in one plane. It is customary practice in constructing these lamps to mount the filamentin definite fixed relationship .with respect to the lugs |93 of the lamp base so that if a lamp is-once positioned to give the most effective light beam the lamps may then be interchanged without losing the lamp adjustment. In this projector a lamp is readily adjusted to proper operating position by the provision of an adjustable socket that is mounted within a lamp supporting member which engages the lamp radiator in predetermined positioning.v loosening the set screw I2I and grasping the connector body |99 to move the lamp with respect to its supporting means until the proper location is found by test to give the greatest illumination in the direction of projection. Upon then tightening the set screw |2| the lamp can beA removed with its` supporting means and can be reinserted or lamps may be changed without altering the positioning of the lamp socket with respect to the lamp radiator.' v The lamp radiator comprises a socketed por tion |25 which is proportioned to rather closely flt around and receive the lamp. The lamp radiator is threaded at its lower open end to receive the lamp supporting means. The socket portion |25 of the lamp radiator is provided with aligned light passages; the /passage |26 providing an opening toward the projector condensing lens, while the passage/|21 opens to a reflector' |28 which is mounted Aupon an extension wall 29 tension against axial displacement by engagement with a fiat face |35 on the supporting part |39 which provides a yielding contact with the reflector that resiliently holds it in place.

The socket wall |25 of the radiator, which is contiguous to the glass wall of the lamp is adapted to rapidly and effectively absorb the heat generated within the lamp. This heat is constantly b eing dissipated by the radiator through the provision-ofu exterior fins of large surface ,area as compared with the area of the wall |25. As shown, the radiator is provided with a plurality of parallel vertical fins |38, and a n |39 which extends across the top of the radiator in the direction of the light path. A transverse fin |49 is shown on the fin |39 to provide additional heat dissipating area.

'I'he iinned radiator and lamp supporting means |29 provide a unitary light. source which is readily removable from the projector` hile assembled.v Means are provided so that 't'v unitary light source will be` accurately heldin proper operating alignment when attachedto the projector. The supporting means for the light source I5 is in the form of a cylindrical sheet metal shell I6 which is attached to the body portion II by bolts`|44 (see Fig. 3).- The shell I6 is provided with an opening |45 which receives and encloses the projection 2'4von the body portion II and is adapted to lie A transfer of heat'from the'radiator tothe shell Adjustment is effected byl I6 is effectively prevented throughl the provision of a heatinsulating lining |46 in the form of a Y layer of sheet cork that attached to the shell inner wall. u The light source is positioned within the shell I6y through thev provision of interengaging means;

shown as cooperating lugs and notches. .As` shown, the oppositely positioned iins |38 are 'i'ormed at their upper edges to provide outwardly extending lugs4 |48, and the shell I6 ,has formed at its upper edge spaced notches |49 which are coordinated with the positioning of the lugs so as to receive the lugs |48 when the light source is inserted within the shell I6. Co-

ordination of positioning ofthe lugs and notches aligns the light source so that the maximum illumination is directed toward the light aper-v gage the part |52 on the radiator.

tures ofthe projector. The radiator is retained within the shell through the provision of a latch |50 having a latching portion |5| that engages a face |52 on' the radiator iin |39., The positioning of the latch |50 on the shell I6 issuch that when the radiator is pushed down for interengagenient of the lugs andnotches the latch end I5 ,will en- 'Theprovision of a close fitting radiator for the lamp provides for eiective dissipation of the lamp heat in that the radiant heat from the lamp'is absorbed by the closely adjacent metallic vwall and is effectively conducted. Withinthe .radiator to the large `fin area provided. 'thereomfrom which the heat is rapidly dissipated.` The surface temperature of the exposedradiator iins-never becomes! excessive as the heat is constantly being taken away by the air flowing up throughthe 'shell |6.

The shell itself is insulated from the radiator by Vthe insulating lining |46 so'that the shell |6re'- mainscool at all times. and-effectively prevents the operator from contacting with the hot parts of the projector. 'Ihe supporting legs ofthe projector are piv. otallyv attached to the extending lug 3 by a clamping bolt so that they may be held in extended posi; tion as shown in Fig; 1 or 'may be moved toa collapsed position-as shown in Fig.'v 3.` The supporting legs comprise like U-shaped members. formed of sheet metal and provided with suitable feet |55; The upstanding legs |53 'or thev'U- shaped members are providedmwith aligned opexif ings torfengagement by a bolt 58 which carries a clamped to provide any desired degree of inclinavtion for theprojector.. \Whenthe legs are moved tothe collapsed position .they lieclosely adjacent.

the yprojector part I3 and substantially within the `lateral connues of the shell I6. The/nlm carrier 2Q also lies' closely adjacent the body portion lI2 and'it is also positioned substantially within the` outline of shell I6 so that the projector when in carrying position is a compact unit. j,

While the forni of apparatus herein described constitutesT a preferred-embodiment oi' the invention, 1n istoybeunderstqoa thawhe inven tion is not limitedlto precise form ofA ap`` paratus, and that changesmay'be madetherein passages.`

a,oss,oss

without departing `from the scope of the invention'which is dened in the appended claims. What is claimed is: Y y 1. In a projector, a light source comprisinga lamp, an enclosing contiguous metal radiator y,for said lamp, said radiator having a light passage therein and external ns thereon extending from end to end of the radiator, and an open ended shell surrounding said .radiator and cooperating i with the ns to provide a plurality of flues 'for heat dissipation.

2. Ina projector, a light source 'comprising a lamp, an enclosing contiguous lmetal radiator for saidv lamp, end to end thereof,la cylindrical sheet metal shell surrounding 'said radiator, said radiatorhavinga plurality of external insextending from and cooperating with the ns toprovide a insulating'lining on said shelln l 3. In a projector, a light source comprising a lamp, a contiguous metal radiator for said lamp,

' plurality of uesfor heat dissipation, and a heat said radiator having a light passage therein, a

cylindrical sheet metal shell surrounding said' radiator, a lightpassage in said shell, and means for removably positioning the radiatorwithinthe ishell withthe light passages aligned, said positioning/ means comprising an intertting means on the radiator and shell,v and a'latchf'removably" retainingsaid means'in engagement.

4. .In a projector, an integral assembled light source removably attachable to a projector asa unit and comprising a lamp; a .contiguous metal radiator for said lamp, said radiator havingv aligned light"passages therein; a reilector, vmeans for attaching said reflector to said radiator at one of said light passages, lamp supporting m'eans removably` attached to. said radiator, a. lamp.`

socket, anctmeans for fastening said lamp socket to said lalnp supporting means inacljusted position to provid a predetermined "positioning, of the, lamp wit 5. In a projectona body portion having a flat 'face'with a groove extending thereacross and a light aperture withinthe confines of saidgroove, a lens supporting portion having a atface-With a grooveextending thereacross .and alight aperture within the -connvesvof said groove, means attaching the faces ``of said portions in'abutting relationshij-with the grooves and light apertures aligned, the grooves forming a -llin chute within the abutting faces ofsaid portions. g

vrespectY to the radiator =1ight ,i

8. In a projector. a body portionV having a fiat surface.. with a groove extending thereacross and f a light aperture lwithin the coniines --of `said groove, a" projectingflug on said body portion exl tending from the'at surface and including a continuationbi the groove, supportinglegs attached -tosaid projecting lug, a lens carrying portion hav'- ing a'iiat surface with "a groove extending therelacross and alight aperture within the confines of said groove, means joiningsaid portions with the at ysurfaces-in abutting relationship` and with the--grooves` and light apertures aligned. the grooves of the'abutting surfaces forming a ilh'n chute between the abutting -Iaces' of said joined 1 `portions,y the groove of tneproecting lug formcontinuationoi one wall of ing a tllm guide in the illn chute, k.

'1. Aprojector comprising a-bod'yportionhavf ing aiiat face' with a groove extending theref across ,and a lightaperture within the coniines of said groove, 'a lenscarrying portion having a iiatface with a groove extending thereacross and of each abutting face,land an aperture glass loosely arranged in each of said recesses, the' recesses being of a depth for free passage of a im through the chute between the glasses.

8. In a projector, a projector body, a iilm carrier mounted on said body, said projector body having aligned light apertures spaced apart in the direction of the light beam, a slot extending through the projector body transversely of the light beam and forming a film chute, a second slot extending through said projector body transversely oi.' the light beam and perpendicularly with respect to the iilm chute, a pair of aperture glasses loosely mounted in said last named slot with a glass on each side of the lm chute, the second slot being of a depth for free passage of a film through the chute between the glasses, and means for retaining the glasses within said slot.

9. In a projector, a projector body, a iilm chute in said body dening a guided path oi travel for a mm,- a rotatable lm advancing sprocket, a bracket supporting said sprocket, means pivotally attaching said bracket to said body portion, and means for retaining said bracket in a position wherein the sprocket stands within the chute and across the path of travel of the film and in a position wherein the sprocket is removed from the path of travel of the iilm.

10. In a projector, a projector body, a lm chute in said projector body, a lm advancing sprocket, an operating shaft for said sprocket, means for rotatably mounting said sprocket shaft comprising a U-shaped bracket, means pivotally attaching said bracket to said projector body for swinging movement thereon, means for movably retaining said bracket in a position for engagement of the sprocket with a film in the chute and in a position wherein the sprocketis removed from engagement with a lm, said retaining means comprising a spring pressed detent, and means for limiting the movement of the sprocket bracket in the direction away from lm engaging position.

11. In a projector, a projector body, said projector body having a lm chute formed therein, film advancing means comprising a sprocket, a shaft xed to said sprocket, an operating handle fixed to said shaft, supporting means for said shaft pivotaliy attached to said body portion for movement thereon, and a detent mounted on the shaft supporting means and engaging the sprock'- et handle and the body portion for frictionally retaining the sprocket handle and supporting means in predetermined positions, said detent comprising a. single coil spring and a detent member at each end thereof engaging said Aoperating handle and said body portion.

RALPH L. LEE.

CERTIFICATE oF CORRECTION.

' Patent No. 2,055,058. March 5. 1956.

RALPH I.. LEE.

It is hereby certified that error appears in the printed specification of the above 'numbered patent requiring correction as follows: Page 4, second column, lines l4- ,and l5, claim 2. strike out the words "end to end thereof, a cylindrical sheet metal shell surrounding said radiator" and insert the same after' "from" in' line 17; and inline l5, same claim, strike` out the comma before "said", and that the said Letters Patent should be read with this Correotion therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of April A. D. 1936.

Leslie "Frazer (Seal) Acting Commissioner of Patents. 

